Yesterday @GroboJason and I did the full calibration on the pH Probe.
Started out by gently lifting the cover and removing the pH probe. I noticed quite a bit of red/brown coloured algae growing on the tip of the probe. I cleaned it with the pH probe cleaning solution and the tooth brush that came with the kit.
Completed the calibration process with the included solutions in the kit and help from Jason. I was lucky because I was on day 21 so right after the calibration I did a complete drain/fill and I replaced the #2 bottle in the Grobo.
So far so good the #2 bottle hasn’t been touched which wasn’t the case beforehand. I will continue to monitor but I think that did the trick.